Jaw clutch

ABSTRACT

A jaw clutch comprising two clutch members and a bushing with jaws at both ends, engaging each of said clutch members, one of which clutch members is mounted on the shaft with a provision for moving along the shaft axis and is constantly pressed by a resilient element against the jaw bushing so that the total axial clearance between the jaws of the bushing and those of the clutch members is smaller than the height of each clutch member jaw at the side of the resilient element. In addition, each jaw of the clutch member at the side of the resilient element has a straight portion and a portion beveled towards the face end.

United States Patent kv. 26, Balkhash, all of, U.S.S.R. 211 AppLNo.847,599 22 Filed -Aug. 5,1969

[45] Patented Aug.3l, 1971 [54] JAW CLUTCH so FieldofSearch .Q l92/l8,l8A, 18 B, 67 R, 148, 149, 108

[ 5 6] References Cited UNITED STATES PATENTS 2,5l9,695 8/1950.Olssonetal. l92/18(.2) 2,787,355 4 1957 Dodge 192/18(X) 2,908,18810/1959 Maybarduk 192/18(X) Primary Examiner-Allan D. HerrmannAttorney-Holman & Stern ABSTRACT: A jaw clutch comprising two clutchmembers and a bushing with jaws at both ends, engaging each of saidclutch members, one of which clutch members is mounted on the shaft witha provision for moving along the shaft axis and is constantly pressed bya resilient element against the jaw bushing so that the total axialclearance between the jaws of the bushing and those of the clutchmembers is smaller than the 2 clamsz Drawing height of each clutchmember jaw at the side of the resilient [52] US. Cl 192/18 A, element.

[92/67 R, 192/ 108 In addition, each jaw of the clutch member at theside of the [51] Int. Cl ..Fl6d 13/22, resilient element has a straightportion and a portion beveled F16d 67/04 towards the face end.

ATEHTEU M1831 197:

SHEET 1 [IF 2 PATENTEU Aucsl ISYl sum 2 OF 2 JAW CLUTCH The presentinvention relates to couplings and more specifically it relates to jawclutches.

Widely known in prior artare the jaw clutches comprising two jaw-typeclutch members rigidly mounted on shafts, and a jaw bushing engagingsaid clutch members. These clutches are intended to transmit torque fromthe driving shaft to the driven shaft, the latter being drivinglycoupled with the jaw bushing.

However, these clutches cannot be employed in load-hoisting machines inwhich the jaw bushing is drivingly linked via the driven shaft with theload being handled, since at the moment when the jaw bushing disengagesone clutch member and engages the other one, the kinematic linkagebetween the bushing and the clutch members is broken because of theconstant clearance between them, which may lead to dropping of the loadand to an accident.

An object of the present invention resides in eliminating the aforesaiddisadvantage.

The main object of the invention is to provide a jaw clutch wherein oneof its members is so designed and arranged with relation to said bushingas to prevent accidental dropping of the conveyed loads and thus toallow the clutch to be used in load-hoisting machines.

This object is achieved by providing a jaw clutch comprised of twoshaft-mounted jaw-type clutch members and a jaw bushing with jaws atboth ends engaging said clutch members wherein, according to theinvention, one of the clutch members is installed on the shaft with aprovision for moving axially over said shaft and is constantly pressedby a resilient element against the jaw bushing so that the summary axialclearance between the jaws of the bushing and those of the clutchmembers would be smaller than the height of each jaw of the clutchmember at the side of the resilient element, each jaw of this clutchmember consisting of a straight portion along its height, and a beveledportion directed to the face end.

This installation on the shaft of one of the clutch members guarantees aconstant engagement of the jaw bushing with at least one of the clutchmembers.

It is preferred that the height of the straight .portion of each jaw ofthe bushing or clutch member be smaller, and the total height of the jawbe larger, than the total axial clearance between the jaws.

The provision of the straight and beveled portions on the clutch memberjaws as well as the relation between the height of the straight portionof the jaws, their total height and the total axial clearance betweenthe jaws ensure an axial movement of the clutch member towards theresilient element until a complete engagement of the jaws is secured.

Now the invention will be described in detail by way of example withreference to the accompanying drawings in which:

FIG. I is a schematic view of a jaw clutch, according to the invention,partly broken away for illustrative clarity; and

FIG. 2 is a diagram showing the connection of the drive to the pullingrolls on a continuous copper-casting plants by means of jaw clutchesaccording to this invention.

The jaw clutch comprises clutch members 1 and 2 (FIG. 1) and a jawbushing 3 having jaws at both ends and a toothed rim 4 on the outersurface thereof.

The bushing 3 is engaged with the clutch members 1 and 2 by means of ahydraulic cylinder 5. The rotating clutch member 1 has a longitudinalslot or keyway 8 and is installed on the drive shaft 6 with a provisionfor axial movement over a key 7 received within the slot.8, whereas thestationary clutch member 2 is rigidly mounted on a support 9.

The clutch member 1 is normally biased toward the jaw bushing 3 by aresilient element 10 in the form of a spring.

This urging of the clutch member 1 toward the bushing 3 is limited by apin 11 secured in the clutch member 1 and entering a longitudinal slot12 in the shaft 6.

The clutch member 1 is pressed against the bushing 3 so that the totalaxial clearance A between the jaws of the clutch members 1, 2 and thejaw bushing 3 is smaller than the height h of the jaw of the clutchmember, 1 whereby the jaw bushing will at all times be engaged with atleast one of the clutch members 1 and/or 2.

Thus, we have the following relation A=A ,+A h where A, is the clearancebetween the jaws of the clutch member 1 and those of the bushing 3;

A is the clearance between the jaws of the clutch member 2 and those ofthe bushing 3.

Each jaw of the clutch member 1 has a straight portion a" along aportion of its height and a beveled portion b," that is, h=a+b A;a A

Thus, the height a? of the straight portion of each jaw of the clutchmember 1 is smaller, and the total height h of the jaw is larger, thanthe total axial clearance A between the jaws of the bushing 3 and thoseof the clutch members 1 and 2.

In a preferred embodiment of the invention the toothed rim 4 isoperatively connected by the gears 13 and 14 to the shaft 15 which hasrigidly mounted thereon a pulling or drawing roll 16 against which theingot 18 pulled out of the crystallizing tank (not shown) is pressed bythe roll 17.

The use of the cooperating jaw clutch is shown with greater detail inFIG. 2 in a multigroove continuous copper casting plant where theclutches are intended for coupling the, centralized drivemeans 19 witheach pair of pulling rolls l6 and 17.

According to the invention the jaw clutch functions as follows:

Assuming that the jaw bushing 3 is initially engaged with the stationaryclutch member 2 and hence'retained against rotation, the rotating clutchmember I will be free for rotation relative thereto, due to theclearance provided between the jaw teeth of the clutch member 1 andthose of the jaw bushing 3. If it is then desired to engage the rotatingclutch member I with the jaw bushing 3 to drive the latter, thehydraulic cylinder 5 is activated and shifts the jaw bushing 3 axiallytowards the left, as seen in FIG. 1.

It should be appreciated that, depending upon the axial position isreached wherein the jaw bushing would normally be engaged with both ofthe clutch members 1 and 2. However, since this jaw bushing is stillretained against rotation by the second clutch member 2, the rotatingfirst clutch member 1 will have its bevelled portions b ride over theteeth of the jaw bushing in camlike manner and thus will be shifted awayfrom the jaw bushing 3 against the influence of the spring 10 whilecontinuing to rotate. Finally, upon further axial shifting of the jawbushing 3, it will become fully disengaged from the stationary clutchmember 2 and thus free to rotate under the influence of the rotatingclutch member 1. As soon as the jaws of the bushing 3 disengage from thejaws of the clutch member 2, the bushing, depending on the weight of theingot 18, either stays immovable (if the ingot is not heavy or jammedup) or tends to turn in the direction of rotation of the clutch member 1(if the ingot 18 is heavy). The rotational speed of the bushing 3 cannotbe greater than that of the clutch member 1 because in such case thejaws of the bushing 3 will contact the straight portion of the jaw ofthe clutch member I. As'the bushing 3 is moved further by the hydrauliccylinder 5, its jaws will engage the jaws of the clutch member 1 andtransmit the torque from the shaft 6 to the roll 16 via the toothed rim4 and the gears 13 and 14.

will continue transmitting the torque to the shaft until its jaws rideover the beveled portion b of the jaws of the clutch member 1. Then,when the jaws of the bushing 3 interact with the beveled portion b" ofthe jaws of the clutch member 1, the latter will be pushed away from thebushing 3, the transmission of the torque will cease and the jaws of thebushing 3 will engage their counterparts on the fixed clutch member 2,in the reverse manner of the operation previously described.

.The industrial testing of the invention has proven its advantages. Inparticular, in the event that it is used as a lifting and/or loweringdevice, freewheeling of the jaw bushing 3 is effectively prevented,since it is maintained at all times in engagement with as least one ofthe clutch members 1 and 2.

We claim:

1. A jaw clutch comprising a shaft, a jaw bushing mounted on said shaftand adapted for rotation relative thereto, said jaw bushing having aplurality of jaws at each end thereof; a pair of clutch members eachhaving jaws respectively adapted to selectively engage the jaws at theopposite ends of said jaw bushing, one of said clutch members beingmounted on said shaft for rotation therewith and the other of saidclutch members being stationary, and a resilient member biasing said oneof said clutch members into engagement with said jaw bushing, each jawof said one of said clutch members and of said bushing having a straightportion along its axial height and a beveled portion towards its freeend, the total clearance between the jaws of said jaw bushing and ofeach of said clutch members being less than the axial height of each jawof said one of said clutch members.

2. A jaw clutch as defined in claim 1 wherein the axial height of thestraight portion of each of said jaws is less than said total clearance,and the total axial height of each of said jaws is greater than saidtotal clearance.

1. A jaw clutch comprising a shaft, a jaw bushing mounted on said shaftand adapted for rotation relative thereto, said jaw bushing having aplurality of jaws at each end thereof; a pair of clutch members eachhaving jaws respectively adapted to selectively engage the jaws at theopposite ends of said jaw bushing, one of said clutch members beingmounted on said shaft for rotation therewith and the other of saidclutch members being stationary, and a resilient member biasing said oneof said clutch members into engagement with said jaw bushing, each jawof said one of said clutch members and of said bushing having a straightportion along its axial height and a beveled portion towards its freeend, the total clearance between the jaws of said jaw bushing and ofeach of said clutch members being less than the axial height of each jawof said one of said clutch members.
 2. A jaw clutch as defined in claim1 wherein the axial height of the straight portion of each of said jawsis less than said total clearance, and the total axial height of each ofsaid jaws is greater than said total clearance.